Challenges of known charging procedures of electric vehicles (e.g., cars), relate to operation range, which can for example be limited to 100 km-200 km, and to long charging time, which is from 3 to 12 hours to charge the vehicle accumulators essentially to full charge. Known embodiments tried to shorten the long charging time by large grid interfaces such as utility power three-phase interfaces, which are generally available within households. However, for charging at home, at office or at a public charging station there are available only slow single-phase options. In known embodiments it has also been tried to shorten charging times by high loading power levels. These embodiments exhibit high temperature, and even ignition risks.
In known embodiments serious kinds of failure arise when the grid, i.e. the electrical network, loses one or more phases from operation. Known three-phase devices must identify the problem situation, shut down and disconnect from the network for the period of the malfunction and return to operation once the fault has been removed. During a grid malfunction the device cannot be used and the charging time is extended even by a ratio of 1:1 with the length of the malfunction (e.g., one hour malfunction causes a one hour extension of charging time). Malfunction of the grid described above may also damage known three-phase devices or even cause a fire.
Patent application document EP2657063 A1 presents a charging device which has conductive and inductive energy transmission interfaces that are connected to an energy storage-side terminal through electric power paths. The embodiments of EP2657063 A1 use several transforming stages causing considerable power losses.
Further, the patent application EP2479059 A1 describes a battery charger for electric vehicles.